Does salt go bad?

[ca2or]

I am at the spin up phase of my new tank and am curious if salt goes bad. I have a bag of Instant Ocean that has been sitting in my storage for almost 3 years but has never been opened. It is basically a rock at this point but is it still usable?

 

[redfishbluefish]

It's a rock because moisture has gotten into it and played with the alk and calc, most likely causing it to precipitate. As far as I'm concerned, it's shot! I wouldn't use it.

To test, break off a chunk and dissolve in water and see if you have a snow-globe effect with the ppt calcium carbonate.

 

[Randy Holmes-Farley Verified Community Expert]

I'd dissolve it and measure the alkalinity. If it is OK for you, the salt will be OK. :)